Mugen112

Car is a '90 Civic. 1.5L DPFI. These numbers seem a bit ridiculous. I can't seem to get my baby to pass emissions. The only testing they do is through the tail pipe. First High speed test is at around 2500rpm, then an idle test right after. The first time I went in, she was smoking ALOT and I knew the motor was getting tired. They went ahead and tested it anyway even tho smoking is an automatic fail. These were the numbers:

HIGH SPEED: HC NORM: 220 CO% NORM = 1.2 CO2% = 11.8
HIGH SPEED: HC RESULT: 832 CO% RESULT= 4.88
FAIL FAIL

IDLE TEST: HC NORM = 220 CO% NORM = 1.20
IDLE TEST: HC RESULT = 512 CO% RESULT = .81
FAIL PASS

There was tons of smoke, so I decided to swap the block over from an eh2 d15b that I had sitting in my garage. When it was in the previous owners car, the motor passed with flying colors. So I swapped the block in with a new headgasket/timingbelt/waterpump and these were the results from the new emission testing..


HIGH SPEED: HC NORM: 220 CO% NORM = 1.2 CO2% = 8.8
HIGH SPEED: HC RESULT: 881 CO% RESULT= 9.0
FAIL FAIL

IDLE TEST: HC NORM = 220 CO% NORM = 1.20
IDLE TEST: HC RESULT = 737 CO% RESULT = 7.27
FAIL FAIL

The test was actually worse this time around.. no smoke coming from the tail pipe at all this time either. So, I decided to giver her a little tune up and throw on an additional cat. The cat that I had was on the manifold which would sit right behind the radiator. This way I'd be running two cats instead of just one. I replaced the plugs with new NGKs, new rotor, and cleaned the cap up a little. I took it out on the highway to make sure that the cats were both heated up. These were the results from doing all of that...


HIGH SPEED: HC NORM: 220 CO% NORM = 1.2 CO2% = 8.1
HIGH SPEED: HC RESULT: 1320 CO% RESULT= 9.91
FAIL FAIL

IDLE TEST: HC NORM = 220 CO% NORM = 1.20
IDLE TEST: HC RESULT = 635 CO% RESULT = 8.12
FAIL FAIL

Again, this time was even WORSE! I'm not sure what else I can do.. I'm going to try changing the oil, a bottle of alcohol, and mess with the timing a little.. but I don't know if they'll fix numbers this bad! Any help would be really appreciated. I'm really trying without much luck, and my motivation is getting lower everytime I go to the emissions control facility to get nothing but more bad news. PLEASE HELP!

Mugen112

no one??

kyden

your cat is junk.

Mugen112

both are? even the one that helped my friend pass emissions about a month ago?

fourthgenhatchB17

Wow, those numbers are horrible! HC stands for hydrocarbons, which is unburnt fuel. Because of that, your CO will naturally read a high percentage (good indicator of a rich condition). You've got something seriosuly wrong here. I bet if I took the cat off my clean running ITR engine, it would put out better numbers than yours!

Whats the full rundown of your engine, ecu, ignition timing specs, cam timing specs, head condition etc etc. ?

non-VTEC

cat and o2 sensor would be a good place to start.

is the ecu modified at all?

TunerN00b

Keep in mind that running excessively rich for some time will kill a cat.

From your reported high HC and CO readings, you're running rich. A new cat would bring down those numbers, for some time, until you burn out that cat as well.

Have a competent tuner take a look at it on a dyno with a wideband. He'll be able to tell you how rich it is actually running, and possibly adjust it (based on what parts you have or don't have).

If you really just want to fake it through the test, advance the timing a bit (if timing isn't part of the check, it is for us in Cali), and dump a bottle of either ISO Heet or Guaranteed to Pass into the tank. Both will help reduce HC.

Mugen112

One of the cats were installed that was used to pass a friend earlier with his stock engine. The head is off of my d15b that was in my '90 civic, then I had an engine from a '92 eh2. The head on the '92 was MPFI, and the one I'm currently running is a DPFI.. I didn't want to do a DPFI to MPFI swap, so I just swapped the blocks. Everything went just great and swapped over just fine. Fired right up. Everything else is just stock. Stock ecu, stock head with some ebay air intake..

PyroProblem

From the numbers it looks like a rich misfire. From what i remember, CO will go up as the a/f richens until you get misfiring a which point HC will skyrocket.
A leaking injector could cause this...
Good luck!

DCFIVER

Dont go changing your cat just yet. A new cat will not bring the HC numbers down enough to pass. Dont worry about the CO right now. Work on the HC which is a definite fuel problem. Either leaking injectors and or possibly a minor tune up (cap, rotor,plugs and wires)



(you may also need to swap ECU's. DPI and MPI will operate the injectors at diffrent intervals and duration. In fact i would do this first then take it back for a retest.)

cr8ter

putting 2 cats on there is not going to help a cat has to be at 2500 degrees to work at its best and the further u put it away from the ex. manifold the crappier its gonna be....u may have leaking injectors and also check the o2 sensor for proper operation....if o2 is not working properly it will not relay the message to the ecu to correct the problem....
O2 Sensor and Catalytic
Converter Test
On pre-OBD II vehicles that dont set a DTC and do not have a driveability
problem, test the O2 (oxygen) sensor and the catalytic
converter with this procedure:
1. Run the engine until it warms up, then monitor O2
sensor voltage by backprobing
the sensor.
– If the voltage rapidly fluctuates between 0.2 and
0.8, the sensor and pgm-fi system are OK go to

– If the voltage is between 0.8 and 1.0, it is running rich so u have to figure out whats causing it to run rich

– If the voltage is between 0 and 0.3, its running too lean
– If the voltage is between 0.4 and 0.6, replace the
sensor.
2. While the engine is idling, disconnect one of the fuel
injector connectors, and monitor the tailpipe
emissions with an exhaust analyzer.
– If the emissions don’t drop within 20 seconds,
replace the cat. The cylinder with
the disconnected injector acts like an air pump,
injecting oxygen into the exhaust. If the
cat is working, this action will
lower tailpipe emissions.
– If the emissions drop within 20 seconds, the
cat is OK. Look for other problems that cause the
high emissions, like a rich or lean mixture, a
fouled plug, or a bad plug wire.

Scott_Tucker

That engine is definitely running rich. If you removed the cat from a properly running engine and measured the CO it would be below about 3%. In your readings you have almost 10%.

DCFIVER

You are incorrect about cat operating temperatures. The cat only needs to reach 600 degrees to work properly.

cr8ter

sorry...let me clarify 2500 is most efficient operating temp...but i thought i did say for it to be at its best....600 is the light off which means that is when it starts to work doesn't mean its working at its best

DCFIVER

Dude, exhaust temperatures do not reach 2500 degrees. Those are cylinder temperatures. 600 is optimal operating temp for the cat. 2500 degrees will melt the substrate. Back to school son...

cr8ter

wow...do u have a smog license?....cuz i do...and one of the qs on there is at what temp does the cat work most effeciently?...the answer is 2500 degrees....do some research and get on my level then we can talk

DCFIVER

LOL show me in black and white. Some literature. You're a freakin moron. Yup ASE certified L1 tech and California licensed Smog tech here son!!! EGT's do NOT reach 2500 degrees under normal operating parameters. I test cats and take egt readings all day. Get your fake *** outta here...

Scott_Tucker

Yes, 2500 F would melt the substrate. Light off is 400 F - 600 F. They run most efficiently 1200 F - 1600 F.

To the OP, throwing another cat on it is not going to fix the problem. Cats are not filters, you can not throw another on to filter the emissions until they are clean. They need the mixture to constantly cycle from rich to lean so that during lean operation they get loaded with oxygen and during rich operation that oxygen is used to convert the bad stuff to less bad stuff. The fact that cat was used to pass someone elses car has no bearing whatsoever as to whether it will clean up emissions enough on your car to pass.

KWayRacing

I am NOT smog certified, but 2500F is more like the meltdown point of catalytic converters. The precious metals used in catalytic converters have melting points just a few hundred degrees above 2500. A catalytic converter will begin to operate at about 600F and reach a max operating temperature of about 1300F.(on a healthy engine) Either way the op must get those HCs down first as stated by DCFiver. Once an engine is known to be in good working condition( good compression, proper valve adjustment) then look at igntion components, then address fuel concerns. The first two are easily handled with basic tools/knowhow. The last is more difficult unless you have a wideband at your disposal and you know what its readings mean. Fortunatley for some of us we have one. Unfortunately for some of us we know at least 3 ppl that have wanted to borrow them and were pissed when we wouldn't just let them use it for a while. Point is buy one, borrow one, pay someone to use theirs for you, but unless you can "see" the actual afr and its change with changes to the fuel system you will be simply guessing and throwing your I/M testing fee away too. Good luck.

cr8ter

i'll dig it up adn post it on here for u idiots

DCFIVER

HaHa we will never hear from him again....

cr8ter

The catalytic convertor is fitted into the front part of the exhaust system as close as physically possible to the engine. it does this with a combination of heat and a precious metal catalyst. The reduction of emissions is caused by a chemical change known as a thermal reaction.

The Convertor is constructed of a case which houses, a normally ceramic, honeycomb monlith, the internal surfaces of which are coated with a combination of platinum and rhodium. Endways on this monolith is visually similar to drinking straws, with hundreds of flow channels that allow gases to come into contact with the catalysts material.

From the year 1993, alomost all-European regsitered cars have been fitted with a three way catalytic convertor. Other types of converter include the two way converter, now superseded due to its lack of ability to reduce nitrous oxides. The three way converter with air, performs the same as the three way convertor, but has clean air pumped into a mid way point to assist the oxidation process.

Operating efficiently the three way converter reduces reduces nitrous oxide into nitrogen, and as with the two-way converter it oxidizes unburned hydrocarbons and carbon monoxide into water / steam and carbon dioxide.

The catalytic converter operates independently from the engine but it does rely on two factors firstly it relies on the exhaust gases to warm it up, the minimum operating temperature is around 400 degrees centigrade and the maximum is around 1300 centigrade. Secondly a clean running engine. Any catalyst can only operate efficiently if the correct amount of oxygen is in the exhaust system. Which brings us to the point of causes of failure. The principle causes of failure are:

1) Carbon pollution, leading to a blockage of the catalyst. Too rich a fuel mixture and / or oil antifreeze entering the exhaust causes this. Carbon deposits initially restrict the operation of the catalyst by coating the available reactive surface. If the fault is allowed to continue the actual exhaust flow through the exhaust is restricted, leading to a reduction in engine power and eventaully total blockage.

2) Convertor melt-down. Usually caused by neat fuel entering the exhaust. Once this neat fuel enters the hot catalyst it ignites and superheats the catalyst and causes melt-down of the ceramic monlith. The melted ceramic may block the exhaust and the fault will show as above. Other signs are the converter glowing red and /or discoloration due to the heat generated on the other surfaces of the converter.

3) Internal fracture of the catalyst. This is usually caused by external / internal physical damage i.e. something hitting the exhaust, internal damage or the actual monolith coming loose internally. The most obvious signs of this fault are exhaust rattles / vibrations.

Catalytic converters are genrally agreed to have a service life of between 50 - 100,000 miles but there are several factors, which will reduce this life drastically. These include:

*

Lead pollution
*

Engine ignition/fueling faults
*

Vehicle use, short journey use prevents the converters from reaching operating temperature.

When Catalytic converters fail prematurely there is usually a reason for it and it is important that this fault is addressed before the replacement is fitted, to prevent the damage that will occur to the new unit. Converter faults take time to show, so it is possible to replace one and the vehicle will function OK, pass all emissions tests etc, but will still have the underlying fault, which will shorten the replacement service life.

When diagnosing catalytic converter faults before testing for emission ssystem faults, ensure that the engine is up to full operating temperature, a road test is recommended. One of the common faults that you will come across is a blocked / restricted catalyst which will show up as a low powered unresponsive engine this can often be confirmed by unbolting or dropping the front of the cat and visually examining the monolith. non starting can also be indicative of a blocked cat.

The ideal method of checking the actual operation of the catalyst is to measure the exhaust gases before and after the converter, with a four gas tester, and measuring the actaul levels of the gas conversion, this is not always practical. Very few cars are fitted with an access point in the front pipe, enabling accurate measurement. The use of a four-gas tester is invaluable in diagnosing fueling faults. For general testing, vehicle specific data needs to be consulted, emission data varies betwen cars. What is acceptable for one may not be acceptable for another.

Scott_Tucker

Is that a poorly written article on catalytic convertors hijacked from an Irish website without giving credit to the original author?

cr8ter

think what u idiots want i proved my side

Scott_Tucker

I don't see how plagiarizing a poorly written non-technical article 'proves' your 'side'.